Odd Sleep Problem with Macbook
 

I bought a Macbook knowing it had a problem in the hopes of fixing it. It boots fine, but right as it gets into OSX the screen goes black. Pressing the space bar or power button will turn the screen back on for a few seconds and then it will turn back off.

This is where it gets really weird, I swapped out the hard drive for a different hard drive with OSX 10.4.11 on it and the system works fine. (The original hard drive had OSX 10.5). So I figured it was a problem with the old hard drive. I upgraded the new hard drive to OSX 10.6 and the problem reappeared!

This makes me believe that something on the logic board is malfunctioning and constantly trying to put the system to sleep but OSX 10.4.11 doesn't recognize this sleep command (It is a 2008 Macbook and came from the factory with OSX 10.5). I also booted from a hard drive with Windows on it without problems.

I plan on opening up the system in a few days and making sure there are no loose cables or obvious problems, does anyone know where on the logic board the sleep functions are controlled or have any ideas as to how to fix the problem?

Have you tried resetting the SMC here

Yes, sorry I should have stated:

Reset SMC
Reset PRAM
Tried 1 stick of RAM in both slots

Also, both hard drives work fine in another Macbook I have.

It definitely seems to be a problem with the Macbook constantly trying to put itself to sleep. I installed InsomniaX and set it to run at startup and now the laptop works because it can't put itself to sleep. Does anyone know if there are any system files that I can delete to make it impossible for the laptop to sleep?

Deleting system files is not going to help even if you could find which ones control the timing. The logic board more than likely has some brain damage and needs to be replaced. If you're not in the mood ($$$) to swap out the logic board yourself, just keep using InsominaX.

Regards.

For anyone having the same problem, I just went back to OSX 10.4 and now the computer works fine. They must've changed the way sleep works in OSX 10.5/6

I was watching a Macbook disassembly video and the person unscrewed the battery connector and sleep switch assembly (Why didn't anyone tell me there's a SLEEP SWITCH! :Shouting:) I'm going to remove mine now and look for signs of corrosion / damage.

I removed the sleep switch, gave all the contacts on the Logic board a good scrubbing with a Q-tip and alcohol, booted the system up and NO MORE SLEEP PROBLEMS! Also, the trackpad click wasn't working before, somehow that problem also got fixed as well!

So for anyone having sleep problems in the future, there is a SLEEP SWITCH! You have to remove the top case to get to it, but before you replace the logic board try giving the sleep switch a good cleaning (also try booting the laptop with the sleep switch removed) it's a **** of a lot cheaper!

any way you could post a link to that video ?

gfs macbook is having the same problem. Or at least seems like it

After removing the top case skip to 7 minutes into this video and it will show you how to remove the battery connector and sleep switch:

YouTube - Take Apart MacBook 13" - Disassembly: Inside # 1

After you disconnect them from the logic board, look at the contacts where it plugged in and see if there is anything that could be shorting them together. Also, try booting the laptop without the sleep switch connected, if it still tries to go to sleep you probably just need to clean off that area of the logic board with some rubbing alcohol and possibly replace the battery connector and sleep switch (Only about $20 from Mac Recycling)